We analyzed complications of the initial 200 cases treated with laparoscopic partial nephrectomy for a suspected renal tumor. Since August 1999, 200 consecutive patients have undergone laparoscopic partial nephrectomy. Mean patient age was 61.6 years, mean body mass index was 29.9 and mean tumor size was 2.9 cm (range 1 to 10). There were 51 central tumors (25%) and 15 solitary kidneys (7.5%). A central tumor was defined as any tumor infiltrating up to the collecting system or renal sinus, during the excision of which entry into and repair of the collecting system was necessary. Mean estimated blood loss was 247 cc and mean operative time was 3.3 hours. Data on complications were obtained from a prospectively maintained computerized database and via telephone calls to patients and/or local referring physicians. A total of 66 patients (33%) had 1 or more complications, which were intraoperative in 11 (5.5%), postoperative in 24 (12%) and delayed in 31 (15.5%). Overall 30 patients (15%) had a non-urological complication and 36 (18%) had a urological complication, including hemorrhage in 19 (9.5%) and urine leakage in 9 (4.5%). Hemorrhage occurred intraoperatively in 7 cases (3.5%) and postoperatively in 4 (2%), while it was delayed in 8 (4%). Of patients with urine leakage none required reoperation, 6 (3%) required a Double-J stent (Medical Engineering Corp., New York, New York) only, 2 (1%) required a Double-J stent with computerized tomography guided drainage and 1 required no treatment. Open conversion was necessary in 2 patients (1%), reoperation was done in 4 (2%) and elective laparoscopic radical nephrectomy was performed in 1 (0.5%). Laparoscopic partial nephrectomy is an advanced procedure with potential for complications. It requires considerable experience with reconstructive laparoscopy.